Integrated optical transmitter and receiver

ABSTRACT

Technology for light detection and ranging (LIDAR) sensor can include an optical signal source, an optical modulation array and optical detector on the same integrated circuit (IC) chip, multi-chip module (MCM) or similar solid-state package.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is divisional of U.S. patent application Ser.No. 15/721,614, filed on Sep. 29, 2017, the contents of which areincorporated herein by reference in their entirety.

BACKGROUND

Techniques or accurately measuring distances is important in a number ofapplications, such as in autonomous driving vehicles, drones, androbotics. A light detection and ranging (LIDAR) system can be used tomeasure the distance to objects by illuminating an area with a laserlight, and calculating the distance to objects by measuring thetime-of-light of the laser light reflected from the objects.Conventional LIDAR systems include a laser, one or more rotating mirrorsand a photodetector or an array of photo detectors. The conventionalLIDAR systems are therefore bulky, and require accurate alignment ofmoving parts, which adds significant costs to the systems. Therefore,there is a continuing need or improved LIDAR systems.

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the disclosure will be apparent from thedetailed description which follows, taken in conjunction with theaccompanying drawings, which together illustrate, by way of example,features of the disclosure; and, wherein:

FIG. 1 is a diagram illustrating a light detection and ranging (LIDAR)integrated circuit (IC) in accordance with an example;

FIG. 2 is a diagram illustrating operation of a LIDAR system inaccordance with an example;

FIG. 3 is a diagram illustrating a LIDAR IC in accordance with anexample; and

FIGS. 4A and 4B are diagrams illustrating a large area optical detectorof a LIDAR IC in accordance an example.

DESCRIPTION OF EMBODIMENTS

Before invention embodiments are described, it is to be understood thatthis disclosure is not limited to the particular structures, processsteps, or materials disclosed herein, but is extended to equivalentsthereof as would be recognized by those ordinarily skilled in therelevant arts. It should also be understood that terminology employedherein is used or describing particular examples or embodiments only andis not intended to be limiting. The same reference numerals in differentdrawings represent the same element.

Numbers provided in low charts and processes are provided or clarity inillustrating steps and operations and do not necessarily indicate aparticular order or sequence.

Furthermore, the described features, structures, or characteristics canbe combined in any suitable manner in one or more embodiments. In thefollowing description, numerous specific details are provided, such asexamples of layouts, distances, network examples, etc., to convey athorough understanding of various invention embodiments. One skilled inthe relevant art will recognize, however, that such detailed embodimentsdo not limit the overall inventive concepts articulated herein, but aremerely representative thereof.

As used in this written description, the singular forms “a,” “an” and“the” include express support or plural referents unless the contextclearly dictates otherwise. Thus, for example, reference to “a layer”includes a plurality of such layers.

Reference throughout this specification to “an example” means that aparticular feature, structure, or characteristic described in connectionwith the example is included in at least one invention embodiment. Thus,appearances of the phrases “in an example” or “in an embodiment” invarious places throughout this specification are not necessarily allreferring to the same embodiment.

As used herein, a plurality of items, structural elements, compositionalelements, and/or materials can be presented in a common list orconvenience. However, these lists should be construed as though eachmember of the list is individually identified as a separate and uniquemember. Thus, no individual member of such list should be construed as ade facto equivalent of any other member of the same list solely based ontheir presentation in a common group without indications to thecontrary. In addition, various invention embodiments and examples can bereferred to herein along with alternatives or the various componentsthereof. It is understood that such embodiments, examples, andalternatives are not to be construed as de facto equivalents of oneanother, but are to be considered as separate and autonomousrepresentations under the present disclosure.

Furthermore, the described features, structures, or characteristics canbe combined in any suitable manner in one or more embodiments. In thefollowing description, numerous specific details are provided, such asexamples of layouts, distances, network examples, etc., to provide athorough understanding of invention embodiments. One skilled in therelevant art will recognize, however, that the technology can bepracticed without one or more of the specific details, or with othermethods, components, layouts, etc. In other instances, well-knownstructures, materials, or operations may not be shown or described indetail to avoid obscuring aspects of the disclosure.

In this disclosure, “comprises,” “comprising,” “containing” and “having”and the like can have the meaning ascribed to them in U.S. Patent lawand can mean “includes,” “including,” and the like, and are generallyinterpreted to be open ended terms. The terms “consisting of” or“consists of” are closed terms, and include only the components,structures, steps, or the like specifically listed in conjunction withsuch terms, as well as that which is in accordance with U.S. Patent law.“Consisting essentially of” or “consists essentially of” have themeaning generally ascribed to them by U.S. Patent law. In particular,such terms are generally closed terms, with the exception of allowinginclusion of additional items, materials, components, steps, orelements, that do not materially affect the basic and novelcharacteristics or unction of the item(s) used in connection therewith.For example, trace elements present in a composition, but not affectingthe composition's nature or characteristics would be permissible ifpresent under the “consisting essentially of” language, even though notexpressly recited in a list of items following such terminology. Whenusing an open ended term in this written description, like “comprising”or “including,” it is understood that direct support should be affordedalso to “consisting essentially of” language as well as “consisting of”language as if stated explicitly and vice versa.

The terms “first,” “second,” “third,” “fourth,” and the like in thedescription and in the claims, if any, are used for distinguishingbetween similar elements and not necessarily or describing a particularsequential or chronological order. It is to be understood that any termsso used are interchangeable under appropriate circumstances such thatthe embodiments described herein are, for example, capable of operationin sequences other than those illustrated or otherwise described herein.Similarly, if a method is described herein as comprising a series ofsteps, the order of such steps as presented herein is not necessarilythe only order in which such steps may be performed, and certain of thestated steps may possibly be omitted and/or certain other steps notdescribed herein may possibly be added to the method.

As used herein, comparative terms such as “increased,” “decreased,”“better,” “worse,” “higher,” “lower,” “enhanced,” and the like refer toa property of a device, component, or activity that is measurablydifferent from other devices, components, or activities in a surroundingor adjacent area, in a single device or in multiple comparable devices,in a group or class, in multiple groups or classes, or as compared tothe known state of the art. For example, a data region that has an“increased” risk of corruption can refer to a region of a memory device,which is more likely to have write errors to it than other regions inthe same memory device. A number of actors can cause such increasedrisk, including location, fabrication process, number of program pulsesapplied to the region, etc.

As used herein, the term “substantially” refers to the complete ornearly complete extent or degree of an action, characteristic, property,state, structure, item, or result. For example, an object that is“substantially” enclosed would mean that the object is either completelyenclosed or nearly completely enclosed. The exact allowable degree ofdeviation from absolute completeness may in some cases, depend on thespecific context. However, generally speaking, the nearness ofcompletion will be so as to have the same overall result as if absoluteand total completion were obtained. The use of “substantially” isequally applicable when used in a negative connotation to refer to thecomplete or near complete lack of an action, characteristic, property,state, structure, item, or result. For example, a composition that is“substantially free of” particles would either completely lackparticles, or so nearly completely lack particles that the effect wouldbe the same as if it completely lacked particles. In other words, acomposition that is “substantially free of” an ingredient or element maystill actually contain such item as long as there is no measurableeffect thereof.

As used herein, the term “about” is used to provide flexibility to anumerical range endpoint by providing that a given value may be “alittle above” or “a little below” the endpoint. However, it is to beunderstood that even when the term “about” is used in the presentspecification in connection with a specific numerical value, thatsupport or the exact numerical value recited apart from the “about”terminology is also provided.

Numerical amounts and data may be expressed or presented herein in arange format. It is to be understood, that such a range format is usedmerely or convenience and brevity, and thus should be interpretedflexibly to include not only the numerical values explicitly recited asthe limits of the range, but also to include all the individualnumerical values or sub-ranges encompassed within that range as if eachnumerical value and sub-range is explicitly recited. As an illustration,a numerical range of “about 1 to about 5” should be interpreted toinclude not only the explicitly recited values of about 1 to about 5,but also include individual values and sub-ranges within the indicatedrange. Thus, included in this numerical range are individual values suchas 2, 3, and 4 and sub-ranges such as from 1-3, from 2-4, and from 3-5,etc., as well as 1, 1.5, 2, 2.3, 3, 3.8, 4, 4.6, 5, and 5.1individually.

This same principle applies to ranges reciting only one numerical valueas a minimum or a maximum. Furthermore, such an interpretation shouldapply regardless of the breadth of the range or the characteristicsbeing described.

As used herein, the term “circuitry” can refer to, be part of, orinclude an Application Specific Integrated Circuit (ASIC), an electroniccircuit, a processor (shared, dedicated, or group), and/or memory(shared, dedicated, or group) that execute one or more software orfirmware programs, a combinational logic circuit, and/or other suitablehardware components that provide the described functionality. In someaspects, the circuitry can be implemented in, or functions associatedwith the circuitry can be implemented by, one or more software orfirmware modules. In some aspects, circuitry can include logic, at leastpartially operable in hardware.

Various techniques, or certain aspects or portions thereof, may take theform of program code (i.e., instructions) embodied in tangible media,such as floppy diskettes, compact disc-read-only memory (CD-ROMs), harddrives, transitory or non-transitory computer readable storage medium,or any other machine-readable storage medium wherein, when the programcode is loaded into and executed by a machine, such as a computer, themachine becomes an apparatus or practicing the various techniques.Circuitry can include hardware, firmware, program code, executable code,computer instructions, and/or software. A non-transitory computerreadable storage medium can be a computer readable storage medium thatdoes not include signal. In the case of program code execution onprogrammable computers, the computing device may include a processor, astorage medium readable by the process or (including volatile andnon-volatile memory and/or storage elements), at least one input device,and at least one output device. The volatile and non-volatile memoryand/or storage elements may be a random-access memory (RAM), erasableprogrammable read only memory (EPROM), lash drive, optical drive,magnetic hard drive, solid state drive, or other medium or storingelectronic data. The node and wireless device may also include atransceiver module (i.e., transceiver), a counter module (i.e.,counter), a processing module (i.e., processor), and/or a clock module(i.e., clock) or timer module (i.e., timer). One or more programs thatmay implement or utilize the various techniques described herein may usean application programming interface (API), reusable controls, and thelike. Such programs may be implemented in a high level procedural orobject oriented programming language to communicate with a computersystem. However, the program(s) may be implemented in assembly ormachine language, if desired. In any case, the language may be acompiled or interpreted language, and combined with hardwareimplementations.

As used herein, the term “processor” can include general purposeprocessors, specialized processors such as central processing units(CPUs), graphics processing units (GPUs), digital signal processors(DSPs), microcontrollers (MCUs), embedded controller (ECs), fieldprogrammable gate arrays (FPGAs), or other types of specializedprocessors, as well as base band processors used in transceivers tosend, receive, and process wireless communications.

It should be understood that many of the functional units described inthis specification may have been labeled as modules, in order to moreparticularly emphasize their implementation independence. For example, amodule may be implemented as a hardware circuit comprising customvery-large-scale integration (LSI) circuits or gate arrays, of-the-shelfsemiconductors such as logic chips, transistors, or other discretecomponents. A module may also be implemented in programmable hardwaredevices such as field programmable gate arrays, programmable arraylogic, programmable logic devices, or the like.

Modules may also be implemented in software or execution by varioustypes of processors. An identified module of executable code may, orinstance, comprise one or more physical or logical blocks of computerinstructions, which may, or instance, be organized as an object,procedure, or unction. Nevertheless, the executables of an identifiedmodule may not be physically located together, but may comprisedisparate instructions stored in different locations which, when joinedlogically together, comprise the module and achieve the stated purposeor the module.

Indeed, a module of executable code may be a single instruction, or manyinstructions, and may even be distributed over several different codesegments, among different programs, and across several memory devices.Similarly, operational data may be identified and illustrated hereinwithin modules, and may be embodied in any suitable form and organizedwithin any suitable type of data structure. The operational data may becollected as a single data set, or may be distributed over differentlocations including over different storage devices, and may exist, atleast partially, merely as electronic signals on a system or network.The modules may be passive or active, including agents operable toperform desired functions.

EXAMPLE EMBODIMENTS

An initial overview of technology embodiments is provided below and thenspecific technology embodiments are described in further detail later.This initial summary is intended to aid readers in understanding thetechnology more quickly but is not intended to identify key features oressential features of the technology nor is it intended to limit thescope of the claimed subject matter.

A light detection and ranging (LIDAR) system can include an opticalsource, an optical phased array (OPA) and optical detector on the sameintegrated circuit (IC) chip, multi-chip module (MCM) or similarsolid-state package and fabricated in the same process low. The LIDARcan include a laser to generate optical signals, an OPA to steertransmission of the optical signals, and a large area detector toreceive reflected optical signals from a large angular field of view(FOV). The time of light between the transmitted optical signals and thereceived reflected optical signals can be used to determine the distanceto objects.

FIG. 1 is a diagram illustrating a light detection and ranging (LDAR)integrated circuit (IC) in accordance with one example. In one aspect,the IC I00 can include an optical signal source 110, an optical phasedarray (OPA) 120, and a large area optical detector 130. In one instancethe optical signal source 110, the OPA 120, and the large area detector130 can be integrated in a semiconductor die (e.g. a single die). Inanother instance, the optical source 110, the OPA 120, and the largearea optical detector 130 can be integrated in a plurality ofsemiconductor die of a multi-chip module (MCM).

In one aspect, the optical signal source 110 can be a laser orgenerating a laser beam. The frequency of the laser beam can optionallybe adjustable. In one aspect, the optical signal source 110 can generatea laser beam parallel to the surface of the IC, MCM or the like.

In one aspect, the OPA 120 can be optically coupled to receive opticalsignals from the optical signal source 110. The optical signal generatedby the optical source 110 can be a rapid series of pulses of opticalsignals. The optical signal from the optical source 110 can be splitamong multiple waveguide paths in the OPA 120. Optical modulators in theOPA 120 can modulate the phase in the multiple waveguide paths. Bymodulating the optical signals in the multiple waveguide paths, the OPA120 can steer the optical signals in two dimensions (2D) of an areailluminated by the optical signals output from the OPA 120. In oneaspect, the OPA 120 can also turn the direction of propagation of thelaser beam from parallel to perpendicular to the surface of the IC, MCMor the like. Therefore, the optical signals can be transmitted from amajor surface (e.g., front) of the IC, MCM or the like.

In one aspect, the large area optical detector 130 can be disposed onthe major surface (e.g., front) of the IC, MCM or the like, and receivelight incident thereon. In one aspect, the large area optical detector130 can receive a large angular field of view of reflected opticalsignals. In one instance, the large area optical detector 130 can be acoherent optical photodetector.

In one aspect, the large area optical detector 130 can include a normalincidence photodetector portion and a waveguide photodetector portion.The waveguide photo detector portion can include an optical waveguideand a photodetector. The optical waveguide can be configured to couplelight to the photodetector of the waveguide photodetector portion.

In one aspect, the optical waveguide can be integrated in a firstsemiconductor layer. In one instance, the first semiconductor layer canbe a N-doped epitaxial silicon semiconductor layer. For example, theepitaxial silicon layer may be disposed on an insulator layer, whereinthe insulator layer is disposed on a substrate to form asemiconductor-on-insulator (SOI) structure. The photodetector of thewaveguide photodetector portion can be integrated in a second and athird semiconductor layer. In one instance, the second semiconductorlayer can be a III-V semiconductor, such as indium phosphide (InP). Thethird semiconductor layer can be a III-V semiconductor, such as aseparate-confinement-heterostructure (SCH), quantum-well (QW)semiconductor.

In one aspect, the normal incidence photodetector portion can bedisposed on the waveguide photodetector portion. The photodetector ofthe normal incidence photodetector portion can be integrated in thethird semiconductor layer and a fourth semiconductor layer. Accordingly,the third semiconductor layer can be utilized to form correspondingparts of the photodetector of both the waveguide photodetector portionand the normal incidence photodetector portion. In one instance, thefourth semiconductor layer can be a P-doped type III-V semiconductor,such as indium phosphide (InP).

In one aspect, a control unit can be coupled to the LIDAR IC 100. Thecontrol unit can control tuning of the optical source 110 or example.The control unit can also control the OPA 120 to steer the light outputin two dimension (2D) or example. For instance, the control unit mayprovide one or more signals to control phase shifts in each of aplurality of waveguides of the OPA 120. The control unit can alsocontrol light detection by the large area optical detector 130 orexample. The control unit can also perform time-of-light (TOF)calculations based upon the light output from the OPA 120 and thereflected light received by the large area optical detector 130.Alternatively, one or more, or all, of the functions of the control unitmay be integrated into the LDAR IC 100.

In one aspect, the position of the OPA 120 relative to the large areaoptical detector 130, when fabricated in an IC, MCM or the like, isfixed. Therefore, the need or alignment and calibration is reduced.Furthermore, the position of the OPA 120 relative to the large areaoptical detector 130 does not change as a result of mechanicalvibrations and stress over the life span of the LIDAR system.

FIG. 2 is a diagram illustrating operation of a light detection andranging (LIDAR) system in accordance with examples of the presenttechnology. In one aspect, the LIDAR system can include an opticalphased array (OPA) 210 and an optical detector 220 fabricated on anintegrated circuit (IC) 230, multi-chip module (MCM) or the like. TheOPA 210 steers a series of optical signals 240 in two dimensions (2D).The optical signals can be pulses of infrared light. The optical signals240 reflect off objects within a target area. For example, opticalsignals scanned horizontally across a target area may reflect of apillar 250, a far wall 260 and a near wall 270. In one aspect, thereflected optical signals 280 are detected by the optical detector 220.A time-of-light (TOF) from when the optical signals 210 were transmittedfrom the LIDAR 200 to when the corresponding reflected optical signals250 were detected can be determined by the LIDAR system. The TOFmeasurements can be made based on direct reflected light, backscatteredlight or a combination thereof. In the case of mobile LIDARapplications, the height, location and orientation of the LIDAR systemcan be combined with the scan position and TOF to determine the locationof objects 250, 260, 270 in three dimensions (3D). The LIDAR system canmeasure distance to a wide range of materials, including metallic andnon-metallic objects, liquids, and gases. In addition, a narrowlaser-beam can map targets with very high resolution.

Accordingly, FIG. 2 is illustrative of an embodiment of a lightdetection and ranging method. Specifically, the LIDAR system outputs theoptical signals 240 using the OPA and the optical detector 220 thendetects a reflected portion of the optical signal. In some embodiments,the outputting of the optical signals 240 can be perpendicular to amajor surface of the integrated circuit 230, and the reflected portiondetected incident on the major surface of the integrated circuit 230.The TOF can then be determined based on the output optical signal andthe reflected portion of the optical signal. In some embodiments,detecting the reflected portion of the optical signal can includecoupling part of the reflection portion of the optical signal by one ormore waveguides. The LIDAR method can be used to determine a location ofone or more objects based on the determined TOF and the location andorientation of the integrated circuit.

FIG. 3 is a diagram illustrating a light detection and ranging (LIDAR)system in accordance with another example. The LDAR system can include aphotonics integrated circuitry (IC) 310 and one or more processing units320. The photonics chip 310 can include a laser 330, an optical splittercoupler 340, a phase modulation array 350, an output array coupler 360,a large area optical detector 370, and an interface 380. The laser 330,the optical splitter coupler 340, the phase modulation array 350, theoutput array coupler 360, the large area optical detector 370, and theinterface 380 can be integrated together in an IC chip, a multi-chipmodule (MCM) or similar solid-state package.

In one aspect, the laser 330 can be a wavelength tunable hybrid silicon(Si)/III-V semiconductor laser that generates infrared light. In oneaspect, the optical splitter coupler 340 can optically couple opticalsignals from the laser 330 to a plurality (N) of waveguides of theoptical phased array 350. The optical splitter coupler 340 can be aone-to-many (1×N) coupler. The optical splitter coupler 340 can be astar coupler. In one instance, the phase modulation array 350 mayinclude 64, 128, 256 or more waveguides and the optical coupler 340 maybe a 1×64, 1×128, 1×256 or corresponding optical coupler. The phasemodulation array 350 can include a plurality of waveguides with opticalphase modulators. The phase of the light traveling in the waveguides ofthe phase modulation array 350 can be varied to steer the opticalsignals in two dimensions (2D) at the output of the output array coupler360. The output array coupler 360 can couple optical signals into freespace. The output array coupler 360 can include a plurality of gratingsto increase the coupling of optical signals into free space.

In one aspect, the large area optical detector 370 can receive a largeangular field of view (FOV) of reflected optical signals. In oneinstance, the large area optical detector 370 can be a coherent opticalphotodetector. In one aspect, the large area optical detector 370 caninclude a normal incidence photodetector portion and a waveguidephotodetector portion. The waveguide photo detector portion can includean optical waveguide and a photodetector. The optical waveguide can beconfigured to couple light to the photodetector of the waveguidephotodetectorportion.

In one aspect, the one or more processing units 320 can control tuningof the wavelength of the laser 330 or example. The one or moreprocessing units 320 can also control the phase modulation array 350 tosteer the light output in two dimensions (2D) for example. For instance,the one or more processing units 320 may provide one or more signals tocontrol phase shifts in each of a plurality of waveguides of the phasemodulation array 350. The one or more processing units 320 can alsocontrol light detection by the large area optical detector 370 forexample. The one or more processing units 320 can also performtime-of-light calculations based upon the light output from the outputarray coupler 360 and the reflected light received by the large areaoptical detector 370. For instance, the one or more processing units 320may calculate distances (D) to objects from the time delay betweentransmitted light pulses and the detected return light pulses accordingto Equation 1,

D=(c·t)/2  (1)

where c is the speed of light, and t is the time delay.

FIGS. 4A and 4B are diagrams illustrating a large area optical detectorof a light detection and ranging (LIDR) integrated circuit (IC) inaccordance an example. FIG. 4A shows a top view illustration of thelarge area optical detector, while FIG. 4B shows a side viewillustration of the large area optical detector. In one aspect, thelarge area optical detector can include a normal incidence photodetectorportion and a waveguide photodetector portion. The large area detectorincluding the normal incidence photodetector portion and the waveguidephotodetector portion can have a large light sensitive area ofapproximately 100 μm² to 100 mm².

In one aspect, the waveguide photodetector portion can include one ormore optical waveguides 405 and a photodetector 410, 415. The opticalwaveguides 405 can be configured to couple light to the photodetector410, 415 of the waveguide photodetector portion. The optical waveguides405 can include a plurality of gratings 420 to increase couple of lightfrom free space into the waveguide photodetector portion. It is to beappreciated that curved lines of the gratings 420 are merely orillustrative purposes. The gratings 420 may have any appropriate ordesired structure or coupling light from free space into the waveguidephotodetector portion.

In one aspect, the one or more optical waveguides 405 can be integratedin a first semiconductor layer. In one instance, the first semiconductorlayer can be disposed on an insulator layer 425, wherein the insulatorlayer 425 is disposed on a substrate 430 to form asemiconductor-on-insulator (SOI) structure. The photodetector 410, 415of the waveguide photodetector portion can be integrated in a second anda third semiconductor layer. In one instance, the second semiconductorlayer can be an N-doped III-V semiconductor, such as indium phosphide(InP). The third semiconductor layer can be a III-V semiconductor, suchas a separate-confinement-heterostructure (SCH), quantum-well (QW)semiconductor.

In one aspect, the normal incidence photodetector portion can include aphotodetector 415, 435 disposed on the photodetector 410, 415 of thewaveguide photodetector portion. The photodetector of the normalincidence photodetector portion can be integrated in the thirdsemiconductor layer and a fourth semiconductor layer. Accordingly, thethird semiconductor layer can be utilized to form a corresponding partof the photodetector of both the waveguide photodetector portion and thenormal incidence photodetector portion. In one instance, the fourthsemiconductor layer can be a P-doped type III-V semiconductor, such asindium phosphide (InP). The large area optical detector can also includea plurality of conductors 440, 445 or coupling the normal incidencephotodetector portion and the waveguide photodetector portion to one ormore other circuits of the LIDR IC, such as an analog to digitalconverter (ADC), interface and/or a control unit.

In one aspect, light 450 can be coupled through the waveguide 405 to thephotodetector 410, 415 of the waveguide photodetector portion. In thelayer of the photodetector 410, 415 of the waveguide photodetectorportion, the light generates electron-hole pairs. A potential voltageacross the conductors 440, 445 sweep the electrons and holes torespective conductors to generate a current in response to the lightincident on the waveguide 405 of the waveguide photodetector portion.Similarly, light 455 incident on the normal incidence photodetectorportion generates electron-hole pairs. The generated electrons and holesare swept to respective conductors to generate a current in response tothe light incident on the normal incidence photodetector portion. Thecurrent can then be converted to a signal representative of thereflected optical signals received by the large area optical detector.

Embodiments of the present technology advantageously provide a low-costsolid state LDAR sensor, as compared to the more expensive and bulkymechanical LIDAR sensor according to the conventional art. The opticaltransmitter and receiver of the LIDAR sensor according to embodiments ofthe present technology can advantageously be implemented in an IC chip,multi-chip module (MCM) or similar solid-state package.

EXAMPLES

The following examples pertain to specific technology embodiments andpoint out specific features, elements, or steps that may be used orotherwise combined in achieving such embodiments.

In one example there is provided a light detection and ranging (LIDR)device comprising: a laser integrated in a chip; a splitter couplerintegrated in the chip, the coupler including an input coupled to thelaser and a plurality of outputs; a phase modulation array integrated inthe chip, the phase modulation array including a plurality of inputseach coupled to a respective one of the plurality of outputs of thesplitter coupler; an output array coupler integrated in the chip, theoutput array coupler coupled to the plurality of outputs of the phasemodulation array; a photodetector integrated in the chip, thephotodetector including a normal incidence photodetector portion; and awaveguide photodetector portion coupled to the normal incidencephotodetector portion.

In one example of a LIDR device, the chip comprises a silicon oninsulator (SOI) substrate.

In one example of a LIDR device, an optical waveguide of the waveguidephotodetectorportion is integrated in a silicon layer of the SOIsubstrate.

In one example of a LIDR device, the photodetector comprises: thewaveguide photodetector portion including, an optical waveguideintegrated in a first semiconductor layer; a first photodetectordisposed on the optical waveguide, wherein the first photodetector isintegrated in a second semiconductor layer and third semiconductorlayer, and wherein the optical waveguide is configured to couple lightto the first photodetector; the normal incidence photodetector portionincluding, a second photodetector disposed on the first photodetector,wherein the second photodetector is integrated in the thirdsemiconductor layer and a fourth semiconductor layer.

In one example of a LDR device, the waveguide photodetector portionfurther includes an input grating coupler integrated in the firstsemiconductor layer and configured to couple light incident on the inputgrating coupler to the optical waveguide.

In one example of a LIDR device, one or more of the second semiconductorlayer, the third semiconductor layer, and the fourth semiconductor layerinclude a group III-V semiconductor.

In one example of a LIDR device, one or more of the second semiconductorlayer, the third semiconductor layer, and the fourth semiconductor layerinclude an indium phosphide (InP) semiconductor.

In one example of a LDR device, the laser includes a frequency tunablehybrid laser.

In one example of a LIDR device, the splitter coupler includes a 1×Nstar coupler.

In one example of a LIDR device, the photodetector comprises a coherentoptical photodetector.

In one example there is provided, an integrated circuit comprising: anoptical signal source; an optical phased array to steer optical signalsfrom the optical signal source in two dimensions (2D); and a large areaoptical detector to receive, from a large angular field of view,reflected optical signals, wherein the large area optical detector isdisposed in a fixed position relative to the optical phased array on theintegrated circuit.

In one example of an integrated circuit, the large area detector isintegrated in a group III-V semiconductor.

In one example of an integrated circuit, the large area detector isintegrated in an indium phosphide (InP) semiconductor.

In one example of an integrated circuit, the large area optical detectorcomprises a coherent optical photodetector.

In one example of an integrated circuit, the large area optical detectorcomprises: a normal incidence photodetector portion; and a waveguidephotodetector portion coupled to the normal incidence photodetectorportion.

In one example of an integrated circuit, the waveguide photodetectorportion comprises: an optical waveguide integrated in a firstsemiconductor layer; and a first photodetector disposed on the opticalwaveguide, wherein the first photodetector is integrated in a secondsemiconductor layer and a third semiconductor layer, and wherein theoptical waveguide is configured to couple light to the firstphotodetector.

In one example of an integrated circuit, the normal incidencephotodetector portion comprises: a second photodetector disposed on thefirst photodetector, wherein the second photodetector is integrated inthe third semiconductor layer and a fourth semiconductor layer.

In one example of an integrated circuit, the waveguide photodetectorportion further includes a grating coupler integrated in the firstsemiconductor layer and configured to couple light incident on thegrating coupler to the optical waveguide.

In one example there is provided, a light detection and ranging (LIDAR)system comprising: a photonics chip including; a laser; a splittercoupler including an input coupled to the laser and a plurality ofoutputs; a phase modulation array, including a plurality of inputs eachcoupled to a respective one of the plurality of outputs of the splittercoupler, the phase modulation array configured to steer optical signalsin two dimensions (2D) at an output of an output array coupler; theoutput array coupler coupled to the plurality of outputs of the phasemodulation array; a large area photodetector configured to receivereflected optical signals from a large angular field of view; and aninterface coupled to the laser, the splitter coupled, the phasemodulation array and the wide area photodetector; and one or moreprocessing units communicatively coupled to the interface of thephotonics chip.

In one example of a light detection and ranging (LIDAR) system, the oneor more processing units are configured to control the steering by thephase modulation array of the optical signal in two dimensions (2D) atoutput of the output array coupler.

In one example of a light detection and ranging (LIDAR) system, the oneor more processing units are configured to determine time of lightinformation of optical signal transmitted by the output array couplerand the reflected optical signal received by the large areaphotodetector.

In one example of a light detection and ranging (LIDAR) system, thelarge area optical detector includes: a normal incidence photodetectorportion; and a waveguide photodetector portion coupled to the normalincidence photodetector portion.

In one example of light detection and ranging (LIDAR) system, thewaveguide photodetector portion comprises: an optical waveguideintegrated in a first semiconductor layer; and a first photodetectordisposed on the optical waveguide, wherein the first photodetector isintegrated in a second semiconductor layer and a third semiconductorlayer, and wherein the optical waveguide is configured to couple lightto the first photodetector.

In one example of light detection and ranging (LIDAR) system, thewaveguide photodetector portion further includes a grating couplerintegrated in the first semiconductor layer and configured to couplelight incident on the grating coupler to the optical waveguide.

In one example of light detection and ranging (LIDAR) system, the normalincidence photodetector portion comprises: a second photodetectordisposed on the first photodetector, wherein the second photodetector isintegrated in the third semiconductor layer and a fourth semiconductorlayer.

In one example there is provided, a light detection and ranging (LIDAR)method comprising: outputting an optical signal output perpendicular toa major surface of an integrated circuit wherein the optical signal issteered in two dimensions; detecting a reflected portion of the opticalsignal incident on the major surface of the integrated circuit; anddetermining a time of light (TOF) based on the output optical signal andthe detected reflected portion of the optical signal.

In one example of a LIDAR method, the method further comprises:determining a location of one or more objects based on the determinedTOF and the location and orientation of the integrated circuit.

In one example of a LIDAR method, detecting the reflected portion of theoptical signal includes coupling part of the reflected portion of theoptical signal by an optical waveguide of the integrated circuit ordetection by a photodetector of the integrated circuit.

In one example of a LIDAR method, detecting the reflected portion of theoptical signal further includes detecting an additional part of thereflected portion of the optical signal incident on the photodetector ofthe integrated circuit.

In one example of a LIDR method, the method further comprises: splittingthe optical signal into an optic al phased array of the integratedcircuit; and modulating the phase of the optical signal in the opticalphased array to steer the optical signal in two dimensions.

While the forgoing examples are illustrative of the principles of thepresent technology in one or more particular applications, it will beapparent to those of ordinary skill in the art that numerousmodifications in form, usage and details of implementation can be madewithout the exercise of inventive faculty, and without departing fromthe principles and concepts of the technology.

1. An integrated circuit comprising: an optical signal source; anoptical phased array configured to steer optical signals from theoptical signal source in two dimensions (2D); and a large area opticaldetector configured to receive reflected optical signals associated witha field of view, wherein the large area optical detector is disposed ina fixed position relative to the optical phased array on the integratedcircuit.
 2. The integrated circuit of claim 1, wherein the large areaoptical detector is integrated in a group III-V semiconductor.
 3. Theintegrated circuit of claim 2, wherein the large area detector isintegrated in an indium phosphide (InP) semiconductor.
 4. The integratedcircuit of claim 1, wherein the large area optical detector comprises acoherent optical photodetector.
 5. The integrated circuit of claim 1,wherein the large area optical detector comprises: a normal incidencephotodetector portion; and a waveguide photodetector portion coupled tothe normal incidence photodetector portion.
 6. The integrated circuit ofclaim 5, wherein the waveguide photodetector portion comprises: anoptical waveguide integrated in a first semiconductor layer; and a firstphotodetector disposed on the optical waveguide, wherein the firstphotodetector is integrated in a second semiconductor layer and a thirdsemiconductor layer, and wherein the optical waveguide is configured tocouple light to the first photodetector.
 7. The integrated circuit ofclaim 6, wherein the normal incidence photodetector portion comprises: asecond photodetector disposed on the first photodetector, and whereinthe second photodetector is integrated in the third semiconductor layerand a fourth semiconductor layer.
 8. The integrated circuit of claim 6,wherein the waveguide photodetector portion further includes a gratingcoupler integrated in the first semiconductor layer and configured tocouple light incident on the grating coupler to the optical waveguide.9. A light detection and ranging (LIDAR) system comprising: a photonicschip including; a laser; a splitter coupler including an input coupledto the laser and a plurality of outputs; a phase modulation arrayincluding a plurality of inputs, each one of the plurality of inputsbeing coupled to a respective one of the plurality of outputs of thesplitter coupler, the phase modulation array being configured to steeroptical signals in two dimensions (2D) at an output of an output arraycoupler that is coupled to the plurality of outputs of the phasemodulation array; a large area photodetector configured to receivereflected optical signals associated with an angular field of view; andan interface coupled to the laser, the splitter coupler, the phasemodulation array, and the large area photodetector; and one or moreprocessors communicatively coupled to the interface of the photonicschip.
 10. The LIDAR system of claim 9, wherein the one or moreprocessors are configured to control the steering of the optical signalsby the phase modulation array in two dimensions (2D) at an output of theoutput array coupler.
 11. The LIDAR system of claim 9, wherein the oneor more processors are configured to determine time of flightinformation of the optical signals transmitted by the output arraycoupler and the reflected optical signals received by the large areaphotodetector.
 12. The LIDAR system of claim 9, wherein the large areaphotodetector includes: a normal incidence photodetector portion; and awaveguide photodetector portion coupled to the normal incidencephotodetector portion.
 13. The LIDAR system of claim 12, wherein thewaveguide photodetector portion comprises: an optical waveguideintegrated in a first semiconductor layer; and a first photodetectordisposed on the optical waveguide, wherein the first photodetector isintegrated in a second semiconductor layer and a third semiconductorlayer, and wherein the optical waveguide is configured to couple lightto the first photodetector.
 14. The LIDAR system of claim 13, whereinthe waveguide photodetector portion further includes a grating couplerintegrated in the first semiconductor layer and configured to couplelight incident on the grating coupler to the optical waveguide.
 15. TheLIDAR system of claim 13, wherein the normal incidence photodetectorportion comprises: a second photodetector disposed on the firstphotodetector; and wherein the second photodetector is integrated in thethird semiconductor layer and a fourth semiconductor layer.